Development and function of the nervous system involves interactions of highly specialized membranes such as interactions of myelin membranes with axons, or nerve ending interaction with appropriate termination sites. We propose to examine the effects of organic lead, organic tin and organic mercury on membranes in the developing nervous system. More specifically, we will investigate the effects of these compounds on the glial processes of myelinogenesis and myelin maturation in both the central and peripheral nervous systems (CNS and PNS). Also because axons and synapses are critically dependent upon membrane macromolecules delivered to them from the nerve cell body by axonal transport, we will investigate effects of heavy metal compounds on this vital neuronal process. Again, we will use both CNS and PNS models. In addition to determining the rate of fast anterograde transport of radioactively labeled proteins, we will characterize the electrophoretic distribution of proteins transported towards nerve endings on the fast, intermediate, and slow waves. We will also determine the distribution of heavy metal compounds during the neonatal period and correlate these results with our biochemical data, as well as with morphological changes resulting from the organo-metal intoxication.